[Mesa-dev] [PATCH] spirv: Fix structure splitting with per-vertex interface arrays.

[Kenneth Graunke]

On Monday, March 14, 2016 5:23:44 PM PDT Jason Ekstrand wrote:
> On Sun, Mar 13, 2016 at 6:08 PM, Kenneth Graunke <kenneth at whitecape.org>
> wrote:
> 
> > We want to use interface_type, not vtn_var->type.  They're normally
> > equivalent, but for geometry/tessellation per-vertex interface arrays,
> > we need to unwrap a level.
> >
> > Otherwise, we tried to iterate a structure members but instead used
> > an array length.  If the array length was longer than the number of
> > fields in the structure, we'd crash.
> > ---
> >  src/compiler/nir/spirv/vtn_variables.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/src/compiler/nir/spirv/vtn_variables.c
> > b/src/compiler/nir/spirv/vtn_variables.c
> > index 31bf416..1628042 100644
> > --- a/src/compiler/nir/spirv/vtn_variables.c
> > +++ b/src/compiler/nir/spirv/vtn_variables.c
> > @@ -923,7 +923,7 @@ var_decoration_cb(struct vtn_builder *b, struct
> > vtn_value *val, int member,
> >           vtn_var->var->data.explicit_location = true;
> >        } else {
> >           assert(vtn_var->members);
> > -         unsigned length = glsl_get_length(vtn_var->type->type);
> > +         unsigned length = glsl_get_length(val->type->type);
> >
> 
> Good catch.  What I think we really want here though is a "without_array"
> helper.  I'm not a huge fan of grabbing the type from the value because
> that comes in from the client and I don't really trust it.

Hmm...okay.  I suppose that would work, because vtn_var->members
existing means that it's a struct...or array of structs.

(I was afraid that we'd have to replicate the logic for deciding
whether it's a normal varying array, or arrayed-interface...but
I guess we don't...)

--Ken
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